Semiconductor memories, such as SRAMs and DRAMs, include of a plurality of memory bit cells arranged in rows and columns. Each memory bit cell is coupled to at least one bit line, which vertically extends across the memory array, and to at least one word line, which horizontally extends across the memory array. The word lines are used to selectively turn on and off transistors of a memory bit cell during read and write operations.
Word line drivers are circuits coupled to the word lines that drive the word lines to particular voltages during the read/write operations. For example, during a write operation, a word line may be driven to 1.6 volts by a word line driver, and the word line may be driven to 1.1 volts during a read operation. The devices that form the word line drivers are conventionally thick-oxide devices in order to prevent damage to the devices when they are subjected to relatively high voltages during the write operations. However, implementing the devices of the word line drivers as thick-oxide devices results in the devices being under-driven during a read operation. The under-driving of the devices during read operations causes the rising of word lines to be unacceptably slow for high-speed memory applications.